There's a trend among fathers documented by sociologists Emily Shafer and Neil Malhotra. Their article measured the effect of a new baby's sex on a parent's gender ideology. Their findings? Men's support for traditional gender roles weakens after they have a daughter; no similar result was documented for new mothers.

This first graph shows the average change in fathers' attitudes before and after having a daughter and a son. The authors note that both men who have daughters (solid grey line) and those who have sons (black dotted line) show a decrease in support for traditional gender roles, but that men who have daughters show a much more steep decline in support.

This second graph shows the average change in mothers' attitudes. Notice that mothers start off with a much lower average level of support for traditional gender roles than fathers and appears to decrease over time. These changes, though, are not statistically significant. So this study offers no evidence mothers' ideologies change the way fathers' do. Bet we all know a father who experienced a change in their thinking about women inspired by looking into the eyes of their own baby daughter.

Cite: Shafer, Emily and Neil Malhotra. 2011. The Effect of a Child's Sex on Support for Traditional Gender Roles. Social Forces 50, 1: 209-222.